#include<cstdio>

 #include<iostream>

 #include<algorithm>

 #include<cstring>

 #include<cmath>

 #include<queue>

 #include<map>

 using namespace std;

 #define MOD 1000000007

 const int INF=0x3f3f3f3f;

 const double eps=1e-;

 typedef long long ll;

 #define cl(a) memset(a,0,sizeof(a))

 #define ts printf("*****\n");

 const int MAXN=;

 int n,m,tt;

 int aa[MAXN];

 int tot,head[MAXN],dp[MAXN][],in[MAXN];

 struct Edge

 {

     int to,next;

 }edge[MAXN];

 void addedge(int u,int v)

 {

     edge[tot].to=v;

     edge[tot].next=head[u];

     head[u]=tot++;

 }

 int dfs(int u)

 {

     for(int i=head[u];i!=-;i=edge[i].next)

     {

         int v=edge[i].to;

         dfs(v);

         dp[u][]+=dp[v][];

         dp[u][]+=max(dp[v][],dp[v][]);

     }

     return max(dp[u][],dp[u][]);

 }

 void init()

 {

     tot=;

     memset(head,-,sizeof(head));

     cl(dp);

     cl(in);

 }

 int main()

 {

     int i,j,k;

     #ifndef ONLINE_JUDGE

     freopen("1.in","r",stdin);

     #endif

     while(scanf("%d",&n)!=EOF)

     {

         init();

         for(i=;i<=n;i++)

            scanf("%d",&dp[i][]);

         int a,b;

         while(scanf("%d%d",&a,&b))

         {

             if(a==&&b==)break;

             addedge(b,a);

             in[a]++;

         }

         int ans=;

         for(i=;i<=n;i++)        //题目的意思就一棵树

         {

             if(!in[i])  ans=dfs(i);

         }

         printf("%d\n",ans);

     }

 }